The Raindrop® hydrogel corneal inlay (ReVision Optics), which has recently received FDA approval, appears to offer a safe and effective treatment for presbyopia, although further studies are needed on the implant’s biocompatibility and its possible impact on the corneal epithelium over the long-term, according to Béatrice Cochener MD, PhD, Brest University Hospital, France.
“This hydrogel inlay works by changing the anterior curvature of the cornea and is a potentially interesting option for suitable presbyopic patients. It provides very good visual outcomes and works particularly well in emmetropic to low hyeperopic patients, with the added advantage of being reversible in the event of any problems. Moreover, the option of concurrent LASIK offers the ability to treat combined ametropia with the placement on the inlay in the non-dominant eye,” Dr Cochener told the French Implant and Refractive Surgery Association (SAFIR) annual meeting
in Paris.
[caption id="attachment_5767" align="alignnone" width="750"]
The Raindrop Inlay at four years[/caption]
The Raindrop corneal inlay is a transparent, permeable, positive meniscus-shaped hydrogel implant which is placed under a flap created by femtosecond laser at a depth of 35 per cent of the corneal thickness, as the recommended threshold to avoid haze. Comprised of approximately 80 per cent water with a refractive index very similar to the cornea, the inlay produces a variation in focal power across the pupil by microscopically altering the surface shape of the cornea.
“The inlay works by gently remodelling the epithelium anteriorly to give a prolate shape to the cornea, with near vision generated by the central zone which has the steepest curvature. The curvature diminishes progressively towards the periphery, creating zones for intermediate and distance vision,” she said.
The goal of the retrospective study of 11 patients carried out at Brest University Hospital, France, was to evaluate the evolution of the corneal epithelium after implantation and correlate it with visual stability over the follow-up period of 48 months.
Patients had an average age of 54 years and were implanted with the Raindrop inlay in the non-dominant eye. The visual results at one month showed that moderate hyperopes were most likely to benefit most from the procedure.
“This is not surprising as the mechanism of action of the implant is to generate a slight myopisation of the eye. The intermediate vision is rarely as good as the near vision, with around 30 per cent of patients needing to wear some correction for computer use and other intermediate tasks,” said Dr Cochener.
Both the optical coherence tomography and aberrometry evaluations confirmed the stability of the implant over the follow-up period, with no evidence of adverse corneal thinning and/or oedema in the study group.
“The remodelling seems to be independent of preoperative and intraoperative factors. However, specific care is required for ocular surface management, with prevention of dry eye to maintain visual performance.
“The anterior stromal above the inlay takes the shape of the inlay when the epithelium thins slightly and increases the profocal zone. Obviously this is a very small group of patients so we still need more prospective studies with longer follow-up to really determine
the stability of this remodelling,”
she concluded.
Béatrice Cochener:
beatrice.cochener@ophtalmologie-chu29.fr